芒果视频下载

簡介

龍卷風是一種(zhong)少(shao)見的局(ju)地性、小尺度、突發性的強對流天(tian)氣，是在強烈(lie)的不穩定的天(tian)氣狀況下(xia)由空氣對流運動造成的、強烈(lie)的、小范圍的空氣渦旋。

從(cong)積(ji)(ji)雨云(yun)中伸(shen)下的(de)猛烈(lie)旋(xuan)轉的(de)漏斗(dou)狀云(yun)樓(lou)。它有(you)(you)(you)時(shi)稍伸(shen)即(ji)隱，有(you)(you)(you)時(shi)懸掛空中或觸(chu)及地面(mian)。龍(long)(long)(long)卷(juan)(juan)(juan)(juan)風(feng)(feng)漏斗(dou)云(yun)的(de)軸一(yi)般(ban)垂直(zhi)(zhi)于地面(mian)，在(zai)發展的(de)后期，當上(shang)下層(ceng)(ceng)風(feng)(feng)速(su)相差較大時(shi)，可(ke)(ke)成傾斜狀或彎曲狀。其下部直(zhi)(zhi)徑(jing)最小(xiao)(xiao)(xiao)的(de)只(zhi)有(you)(you)(you)幾米(mi)(mi)，一(yi)般(ban)為(wei)數(shu)百米(mi)(mi)，最大可(ke)(ke)達(da)千米(mi)(mi)以(yi)上(shang)，上(shang)部直(zhi)(zhi)徑(jing)一(yi)般(ban)為(wei)數(shu)千米(mi)(mi)，最大可(ke)(ke)達(da)10公(gong)(gong)里(li)。龍(long)(long)(long)卷(juan)(juan)(juan)(juan)風(feng)(feng)的(de)尺度很小(xiao)(xiao)(xiao)，中心(xin)氣(qi)(qi)壓很低(di)，造(zao)成很大的(de)水(shui)(shui)平氣(qi)(qi)壓梯度，從(cong)而導致強(qiang)烈(lie)的(de)風(feng)(feng)速(su)，中心(xin)風(feng)(feng)速(su)可(ke)(ke)達(da)100-200米(mi)(mi)/秒。由(you)于氣(qi)(qi)流的(de)旋(xuan)轉力很強(qiang)，常將地面(mian)的(de)水(shui)(shui)、塵土、泥沙挾卷(juan)(juan)(juan)(juan)而起，其破壞(huai)力變(bian)動范圍很大，弱者僅(jin)能卷(juan)(juan)(juan)(juan)起稻草捆和(或)衣物(wu)強(qiang)者可(ke)(ke)按樹倒(dao)屋，至把人、畜也(ye)一(yi)并升起，經過水(shui)(shui)面(mian)時(shi)可(ke)(ke)吸水(shui)(shui)上(shang)升如柱，(這(zhe)時(shi)稱(cheng)水(shui)(shui)龍(long)(long)(long)卷(juan)(juan)(juan)(juan))，所(suo)以(yi)龍(long)(long)(long)卷(juan)(juan)(juan)(juan)風(feng)(feng)范圍雖小(xiao)(xiao)(xiao)，但造(zao)成的(de)災情卻很嚴重(zhong)。龍(long)(long)(long)卷(juan)(juan)(juan)(juan)風(feng)(feng)的(de)移(yi)向、移(yi)速(su)是由(you)其母云(yun)(產生龍(long)(long)(long)卷(juan)(juan)(juan)(juan)的(de)積(ji)(ji)雨云(yun))的(de)移(yi)動決(jue)定的(de)，母云(yun)的(de)移(yi)速(su)通常為(wei)每小(xiao)(xiao)(xiao)時(shi)40-50公(gong)(gong)里(li)，最快可(ke)(ke)達(da)90-100公(gong)(gong)里(li)。其移(yi)動路徑(jing)多呈直(zhi)(zhi)線，一(yi)般(ban)只(zhi)有(you)(you)(you)幾公(gong)(gong)里(li)，個(ge)別可(ke)(ke)達(da)數(shu)十公(gong)(gong)里(li)。龍(long)(long)(long)卷(juan)(juan)(juan)(juan)風(feng)(feng)是強(qiang)對流天(tian)氣(qi)(qi)的(de)產物(wu)，常發生于北緯20-50度地帶低(di)層(ceng)(ceng)大氣(qi)(qi)層(ceng)(ceng)結具(ju)有(you)(you)(you)很大對流不穩定的(de)地區，往往與鋒面(mian)、氣(qi)(qi)旋(xuan)或非熱帶性雷(lei)暴(bao)相伴隨(sui)。登(deng)陸(lu)(lu)后的(de)熱帶氣(qi)(qi)旋(xuan)移(yi)到(dao)中緯趨向衰亡時(shi)，也(ye)很易出(chu)現龍(long)(long)(long)卷(juan)(juan)(juan)(juan)風(feng)(feng)，有(you)(you)(you)時(shi)還可(ke)(ke)出(chu)現在(zai)熱帶地區。根據龍(long)(long)(long)卷(juan)(juan)(juan)(juan)風(feng)(feng)產生的(de)地區可(ke)(ke)分為(wei)陸(lu)(lu)龍(long)(long)(long)卷(juan)(juan)(juan)(juan)(產生在(zai)陸(lu)(lu)地上(shang)空)和水(shui)(shui)龍(long)(long)(long)卷(juan)(juan)(juan)(juan)(產生在(zai)海面(mian)或水(shui)(shui)面(mian)上(shang)空)。龍(long)(long)(long)卷(juan)(juan)(juan)(juan)風(feng)(feng)很難預報，測雨雷(lei)達(da)也(ye)未曾直(zhi)(zhi)接觀(guan)測到(dao)過。

基本特點

龍(long)卷(juan)風(feng)，是(shi)一種(zhong)具有(you)一定破壞力的自然現(xian)象。一般(ban)情況下，龍(long)卷(juan)風(feng)是(shi)一種(zhong)氣旋(xuan)。它在(zai)接觸(chu)地面(mian)時(shi)(shi)，直徑從(cong)幾米到(dao)(dao)幾百米，平(ping)均為250米左(zuo)右，最大(da)為1000米左(zuo)右。在(zai)空中(zhong)直徑可(ke)有(you)幾千(qian)米，最大(da)有(you)10千(qian)米。極(ji)大(da)風(feng)速每小(xiao)時(shi)(shi)可(ke)達(da)150千(qian)米至450千(qian)米，龍(long)卷(juan)風(feng)持續時(shi)(shi)間，一般(ban)僅幾分(fen)鐘，最長不(bu)過幾小(xiao)時(shi)(shi)。所到(dao)(dao)之處(chu)萬(wan)物遭劫。龍(long)卷(juan)風(feng)漏斗狀(zhuang)中(zhong)心由吸起的塵土和凝聚的水氣組(zu)成可(ke)見的“龍(long)嘴”。在(zai)海(hai)洋上，尤(you)其是(shi)在(zai)熱帶，類似的景象在(zai)發生稱(cheng)為海(hai)上龍(long)卷(juan)風(feng)。

龍卷風通(tong)常是極其快速(su)的，每秒鐘100米(mi)的風速(su)不足為奇，甚至達到(dao)每秒鐘175米(mi)以上(shang)，比12級臺風還要大五、六倍(bei)。風的范圍很(hen)小(xiao)(xiao)，一般直(zhi)徑(jing)(jing)只有25~100米(mi)，只在極少數的情況下(xia)直(zhi)徑(jing)(jing)才(cai)達到(dao)一公里以上(shang)；從發(fa)生到(dao)消(xiao)失(shi)只有幾(ji)分種，最多(duo)幾(ji)個小(xiao)(xiao)時。

大多數龍(long)卷(juan)(juan)風在(zai)北半(ban)球是逆(ni)時針(zhen)(zhen)旋(xuan)轉，在(zai)南半(ban)球是順(shun)時針(zhen)(zhen)，也有(you)例外情(qing)況(kuang)。卷(juan)(juan)風形成的確切機理仍在(zai)研究中，一般(ban)認為是與大氣的劇烈活動有(you)關。

從19世紀以來，天氣預(yu)報(bao)的準(zhun)確性(xing)大大提高，氣象雷達(da)能(neng)夠監測到龍卷風、颶(ju)風等各(ge)種(zhong)災害風暴。

龍(long)卷(juan)風經(jing)過(guo)之(zhi)處，常(chang)會發(fa)生拔起大樹、掀翻車輛、摧毀建筑(zhu)物(wu)等現(xian)象，它往(wang)(wang)往(wang)(wang)使成片莊(zhuang)稼、成萬株(zhu)果木瞬間被毀，令(ling)交通中(zhong)斷(duan)，房屋倒塌，人畜生命(ming)和經(jing)濟(ji)遭受損失。

形成條件

龍卷風這(zhe)種自然(ran)現象是云(yun)層中雷暴(bao)的產物，具體的說，龍卷風就是雷暴(bao)巨大能量中的一小部分在很小的區域內集(ji)中釋放的一種形(xing)式(shi)。

龍(long)卷(juan)風(feng)的形成(cheng)可以(yi)分(fen)為四個階段(duan)：

（1）大氣的(de)不穩定性產生強烈的(de)上(shang)升氣流，由于急流中的(de)最大過(guo)境氣流的(de)影響，它(ta)被(bei)進一(yi)步加強。

（2）由(you)于與(yu)在垂直方向(xiang)(xiang)上(shang)(shang)速度和方向(xiang)(xiang)均有(you)切變的風相互作(zuo)用，上(shang)(shang)升氣流在對流層的中(zhong)部開(kai)始旋轉(zhuan)，形成中(zhong)尺度氣旋。

（3）隨著中尺(chi)度氣旋(xuan)向(xiang)地面發展和(he)向(xiang)上伸展，它(ta)本(ben)身(shen)變細并增(zeng)強。同時，一個小面積的增(zeng)強輔合，即初生(sheng)的龍卷在(zai)氣旋(xuan)內(nei)部(bu)形(xing)成，產生(sheng)氣旋(xuan)的同樣過程，形(xing)成龍卷核心。

（4）龍卷核心中(zhong)的(de)(de)旋轉與氣旋中(zhong)的(de)(de)不同，它的(de)(de)強度足以使龍卷一直伸展到地面(mian)。當發展的(de)(de)渦旋到達地面(mian)高度時，地面(mian)氣壓急(ji)劇下(xia)降，地面(mian)風(feng)速(su)急(ji)劇上(shang)升，形成龍卷風(feng)。

探測方法

多普勒天氣雷達探測

龍(long)(long)卷(juan)風發(fa)生至(zhi)消散的(de)(de)時間(jian)短，作用面積很小，以至(zhi)于現(xian)有(you)(you)的(de)(de)探(tan)測儀器沒有(you)(you)足夠的(de)(de)靈(ling)敏度來對龍(long)(long)卷(juan)風進行準確的(de)(de)觀測。相對來說，多普(pu)勒雷達(da)是比(bi)較有(you)(you)效(xiao)和(he)常用的(de)(de)一(yi)種(zhong)(zhong)觀測儀器。多普(pu)勒雷達(da)對準龍(long)(long)卷(juan)風發(fa)出的(de)(de)微波束，微波信(xin)(xin)號(hao)被(bei)龍(long)(long)卷(juan)風中(zhong)的(de)(de)碎屑(xie)和(he)雨點反(fan)射(she)后重(zhong)被(bei)雷達(da)接(jie)(jie)收。如果龍(long)(long)卷(juan)風遠離(li)雷達(da)而(er)去(qu)，反(fan)射(she)回的(de)(de)微波信(xin)(xin)號(hao)頻(pin)率將向低頻(pin)方向移(yi)動(dong)；反(fan)之，如果龍(long)(long)卷(juan)風越來越接(jie)(jie)近雷達(da)，則(ze)反(fan)射(she)回的(de)(de)信(xin)(xin)號(hao)將向高頻(pin)方向移(yi)動(dong)。這種(zhong)(zhong)現(xian)象(xiang)被(bei)稱為多普(pu)勒頻(pin)移(yi)。接(jie)(jie)收到(dao)信(xin)(xin)號(hao)后，雷達(da)操(cao)作人員就可(ke)以通過分(fen)析頻(pin)移(yi)數(shu)據(ju)，計算出龍(long)(long)卷(juan)風的(de)(de)速度和(he)移(yi)動(dong)方向。

雙極化天氣雷達探測

雙(shuang)(shuang)極(ji)化(hua)技(ji)術的(de)(de)出現對(dui)多(duo)(duo)普(pu)(pu)勒(le)天氣雷達(da)(da)探測(ce)中氣旋和龍卷進行了有(you)(you)力(li)的(de)(de)補(bu)充，全面提升了對(dui)龍卷微物理特征分析(xi)與預警預報水(shui)平。①由(you)于(yu)(yu)多(duo)(duo)普(pu)(pu)勒(le)天氣雷達(da)(da)對(dui)較小尺度的(de)(de)龍卷渦旋探測(ce)需要具有(you)(you)良好的(de)(de)空間(jian)分辨率，然而對(dui)雙(shuang)(shuang)極(ji)化(hua)探測(ce)而言(yan)并(bing)不需要太高的(de)(de)精(jing)度。②雙(shuang)(shuang)極(ji)化(hua)特征信(xin)號(hao)不同于(yu)(yu)多(duo)(duo)普(pu)(pu)勒(le)特征信(xin)號(hao)，由(you)于(yu)(yu)其(qi)是“各向同性”的(de)(de)，所以(yi)并(bing)不依(yi)賴于(yu)(yu)觀測(ce)角(jiao)度的(de)(de)變化(hua)。③當龍卷在夜間(jian)發(fa)生或被大量降水(shui)包裹著難(nan)以(yi)通過多(duo)(duo)普(pu)(pu)勒(le)雷達(da)(da)觀測(ce)發(fa)現時，雙(shuang)(shuang)極(ji)化(hua)信(xin)息更(geng)能有(you)(you)效地(di)將其(qi)識別。

快速掃描雷達探測

Wurman設(she)計開發了第一(yi)(yi)部X波段移動(dong)式快速(su)掃(sao)描雷(lei)達(da)(da) Rapid DOW，該雷(lei)達(da)(da)每(mei)7秒可以完成(cheng)一(yi)(yi)次360°的體(ti)掃(sao)，在14秒的時間(jian)里可以探測到(dao) 12個波束(shu)范圍(wei)的數據，并且其(qi)距(ju)離分辨率(lv)達(da)(da)到(dao)11米，更易于對龍卷三維(wei)結構(gou)進行(xing)研(yan)究。從當前對龍卷的探測技(ji)術(shu)來看，快速(su)掃(sao)描雷(lei)達(da)(da)在時空(kong)尺度(du)上對龍卷觀測獨特優(you)勢。而美國計劃的下一(yi)(yi)代天氣雷(lei)達(da)(da)網絡也定位為多(duo)功能相控陣雷(lei)達(da)(da)。所以可見該技(ji)術(shu)未(wei)來必(bi)將成(cheng)為研(yan)究該類天氣的主(zhu)要手(shou)段。

主要類型

多漩渦龍卷風

多漩(xuan)(xuan)渦龍(long)卷風(feng)（Multiple vortex）指(zhi)帶有(you)兩(liang)股以上(shang)圍繞(rao)同(tong)一個中心旋(xuan)轉的(de)(de)漩(xuan)(xuan)渦的(de)(de)龍(long)卷風(feng)。多漩(xuan)(xuan)渦結構經(jing)常出現在劇烈(lie)的(de)(de)龍(long)卷風(feng)上(shang)，并且這些小漩(xuan)(xuan)渦在主龍(long)卷風(feng)經(jing)過(guo)的(de)(de)地區(qu)上(shang)往(wang)往(wang)會造成更大的(de)(de)破壞。

水龍卷

水(shui)(shui)(shui)龍(long)(long)(long)(long)卷(juan)（或(huo)稱海(hai)(hai)龍(long)(long)(long)(long)卷(juan)，英(ying)文：waterspout）可以簡(jian)單地(di)定義為(wei)水(shui)(shui)(shui)上(shang)的(de)(de)(de)龍(long)(long)(long)(long)卷(juan)風，通(tong)(tong)常(chang)(chang)(chang)意思是在(zai)(zai)水(shui)(shui)(shui)上(shang)的(de)(de)(de)非(fei)超級單體(ti)龍(long)(long)(long)(long)卷(juan)風。世界各地(di)的(de)(de)(de)海(hai)(hai)洋和湖泊等都可能(neng)出現水(shui)(shui)(shui)龍(long)(long)(long)(long)卷(juan)。在(zai)(zai)美國(guo)，水(shui)(shui)(shui)龍(long)(long)(long)(long)卷(juan)通(tong)(tong)常(chang)(chang)(chang)發生(sheng)在(zai)(zai)美國(guo)東南(nan)部(bu)海(hai)(hai)岸，尤其在(zai)(zai)佛羅里達(da)南(nan)部(bu)和墨西哥灣(wan)。水(shui)(shui)(shui)龍(long)(long)(long)(long)卷(juan)雖在(zai)(zai)定義上(shang)是龍(long)(long)(long)(long)卷(juan)風的(de)(de)(de)一種(zhong)，不(bu)過其破壞性要(yao)比最(zui)強大的(de)(de)(de)大草原龍(long)(long)(long)(long)卷(juan)風小(xiao)，但是它們仍(reng)然是相(xiang)當(dang)危險的(de)(de)(de)。水(shui)(shui)(shui)龍(long)(long)(long)(long)卷(juan)能(neng)吹翻小(xiao)船(chuan)，毀壞船(chuan)只(zhi)，當(dang)吹襲陸地(di)時就有更大的(de)(de)(de)破壞，并奪去生(sheng)命。當(dang)水(shui)(shui)(shui)龍(long)(long)(long)(long)卷(juan)很可能(neng)產生(sheng)或(huo)在(zai)(zai)海(hai)(hai)岸水(shui)(shui)(shui)域(yu)上(shang)已(yi)經看得(de)見(jian)的(de)(de)(de)時候，美國(guo)國(guo)家氣象局(ju)將會(hui)經常(chang)(chang)(chang)發出特(te)殊的(de)(de)(de)海(hai)(hai)上(shang)警(jing)告，或(huo)者當(dang)水(shui)(shui)(shui)龍(long)(long)(long)(long)卷(juan)會(hui)向(xiang)陸地(di)移動時發出龍(long)(long)(long)(long)卷(juan)風警(jing)告。

陸龍卷

陸龍(long)(long)卷(juan)(juan)（英文：landspout，美國(guo)國(guo)家(jia)氣象(xiang)局稱(cheng)dust-tube tornado）用以描述一(yi)種和(he)中(zhong)尺(chi)度(du)(du)氣旋沒(mei)有關聯的龍(long)(long)卷(juan)(juan)風(feng)。陸龍(long)(long)卷(juan)(juan)和(he)水龍(long)(long)卷(juan)(juan)有一(yi)些(xie)相(xiang)同(tong)的特點，例(li)如強度(du)(du)相(xiang)對較(jiao)(jiao)弱、持續時間(jian)短、冷(leng)凝形成的漏斗(dou)云(yun)較(jiao)(jiao)小且經常不(bu)接觸地面等。雖然強度(du)(du)相(xiang)對較(jiao)(jiao)弱，但陸龍(long)(long)卷(juan)(juan)依(yi)然會帶來(lai)強風(feng)和(he)嚴(yan)重破壞。

火龍卷

火龍(long)(long)卷(juan)，非常罕見(jian)的龍(long)(long)卷(juan)風(feng)(feng)形態，由(you)陸龍(long)(long)卷(juan)與火焰(yan)(yan)的結合。2010年，位于南(nan)半球的巴西遭(zao)遇罕見(jian)的干旱少(shao)雨(yu)天氣，全國多地燃(ran)起(qi)了山火。8月24日(ri)，巴西圣保(bao)羅市(shi)一(yi)處火點刮起(qi)了龍(long)(long)卷(juan)風(feng)(feng)，形成(cheng)了罕見(jian)的火焰(yan)(yan)龍(long)(long)卷(juan)風(feng)(feng)景(jing)觀。龍(long)(long)卷(juan)風(feng)(feng)夾起(qi)火焰(yan)(yan)高達數米，像一(yi)條(tiao)(tiao)巨大(da)的火龍(long)(long)旋(xuan)轉前進。這條(tiao)(tiao)“火龍(long)(long)風(feng)(feng)”于24日(ri)被拍(pai)攝到。“火龍(long)(long)”在(zai)燃(ran)燒(shao)的田(tian)野上(shang)飛舞高約數米高，阻斷了一(yi)條(tiao)(tiao)公路。為了熄(xi)滅這條(tiao)(tiao)“火龍(long)(long)”，當地出(chu)動了直升機。

出(chu)現“火(huo)龍風”的(de)地(di)區已經有(you)3個月沒有(you)下雨。異(yi)常(chang)干旱的(de)天(tian)氣和強(qiang)勁的(de)風勢助長了此(ci)處的(de)火(huo)勢。巴(ba)西全(quan)球電視臺報道稱(cheng)，圣保羅(luo)地(di)區的(de)空氣干燥(zao)程(cheng)度已趕上(shang)了撒(sa)哈拉沙漠。

EF分級

龍卷風按(an)它的破壞程度不(bu)同，分為0-5增(zeng)強藤田級(ji)數，簡單來說就稱為EF級(ji)，由1971年(nian)芝加(jia)哥(ge)大(da)學的藤田哲也博士所提出(chu)。

EF0級：風(feng)速在(zai)65-85英里(li)每小時，約合105-137公里(li)每小時，雖然較弱，但還是足以把樹枝吹斷(duan)，把較輕的碎片卷起(qi)來擊碎玻璃，一些(xie)煙囪會被吹斷(duan)。（出現(xian)幾率極(ji)高，53.5%）

EF1級：風速(su)在每(mei)小時(shi)(shi)86-110英里(li)(li)每(mei)小時(shi)(shi)，約合138-177公里(li)(li)每(mei)小時(shi)(shi)，它(ta)們(men)可以把屋頂吹走，把活動板房給吹翻，一些(xie)較輕的汽車(che)會被吹翻或(huo)刮離路面(mian)。（出現幾率較高，31.6%）

EF2級：風速在111-135英(ying)里每(mei)小(xiao)(xiao)時，約合178-217公(gong)里每(mei)小(xiao)(xiao)時，它們可以把(ba)沉重(zhong)的甘草包吹出去幾(ji)百米遠，把(ba)一棵大樹連根拔(ba)起，貨車可以刮離路面。（出現(xian)幾(ji)率中等偏低，10.7%）

EF3級(ji)：風速(su)在136-165英(ying)里每(mei)小時，約合218-266公(gong)里每(mei)小時，它們可以把一輛較重(zhong)汽(qi)車吹翻，樹(shu)木被吹離(li)地面，房(fang)屋一大(da)半被毀，火車脫離(li)軌(gui)道。（出現幾率低，3.4%）

EF4級：風速(su)在166-200英里(li)每小(xiao)時，約合267-322公里(li)每小(xiao)時，它們可(ke)以(yi)把一輛汽車刮飛，把一幢牢固的房屋夷為平地，樹(shu)木被刮到幾百米高空(kong)。（出現幾率很(hen)低，0.7%）

EF5級(ji)：EF5級(ji)風速超過每小(xiao)時(shi)(shi)(shi)200英里(li)每小(xiao)時(shi)(shi)(shi)，也(ye)就(jiu)是(shi)超過了322公(gong)里(li)每小(xiao)時(shi)(shi)(shi)，房(fang)屋完(wan)全(quan)吹毀(hui)，汽車完(wan)全(quan)刮(gua)飛(fei)，路面上的瀝青也(ye)會被(bei)刮(gua)走(zou)，貨車、火車、列車全(quan)部(bu)脫離地面。（出現(xian)幾(ji)率較低偏高，20%—45%）

龍(long)(long)卷(juan)風(feng)(feng)并沒(mei)有(you)EF6級(ji)。那是(shi)(shi)(shi)絕對不可能的，這(zhe)是(shi)(shi)(shi)根據(ju)物(wu)理和氣(qi)象學推算出來(lai)的，所(suo)以，1999年5月3日(ri)俄克(ke)拉荷馬(ma)城的龍(long)(long)卷(juan)風(feng)(feng)不是(shi)(shi)(shi)EF6級(ji)，而(er)是(shi)(shi)(shi)EF5級(ji)，但是(shi)(shi)(shi)電視(shi)臺也報(bao)道過當天超過每小時512公里的風(feng)(feng)速，而(er)且在一個(ge)雷達上估測到(dao)了(le)318英里每小時的大風(feng)(feng)，這(zhe)就(jiu)表明龍(long)(long)卷(juan)風(feng)(feng)的破壞力量很(hen)大，不要相信有(you)EF6級(ji)龍(long)(long)卷(juan)風(feng)(feng)，那是(shi)(shi)(shi)虛構。

除此之外，龍(long)卷風還可(ke)以(yi)分(fen)為4個形(xing)狀(zhuang)：

煙囪龍(long)卷風：輪(lun)廓直，比較粗壯，強度中等(deng)，一般在EF2—EF4級(ji)左(zuo)右。

繩(sheng)形龍卷(juan)風：纖細，輪(lun)廓(kuo)教彎，強度弱(ruo)，一般在EF0—EF2左右。

楔形龍(long)卷風(feng)：長度較寬(kuan)(kuan)，可達(da)1.5公里(li)，寬(kuan)(kuan)度超(chao)過高度，強(qiang)度強(qiang)，一(yi)般在EF4—EF5左右。

雙胞胎龍卷(juan)風：兩個(ge)龍卷(juan)風，有的(de)粗，有的(de)細，強度不定。

易發國家和地區

全球除南極洲(zhou)以外的(de)(de)大洲(zhou)都(dou)有龍(long)卷風(feng)(feng)(feng)記錄，龍(long)卷風(feng)(feng)(feng)主要(yao)發(fa)(fa)生在中緯度地區，其(qi)中美國(guo)(guo)發(fa)(fa)生最為(wei)頻繁(fan)，堪稱“龍(long)卷王(wang)國(guo)(guo)”，被稱為(wei)“龍(long)卷風(feng)(feng)(feng)之(zhi)鄉”，其(qi)發(fa)(fa)生的(de)(de)龍(long)卷風(feng)(feng)(feng)約占全球龍(long)卷風(feng)(feng)(feng)總數的(de)(de)75%；其(qi)次為(wei)加拿大；歐洲(zhou)西部和中部、中國(guo)(guo)、孟加拉國(guo)(guo)、日本(ben)、澳大利亞、新西蘭、南非和阿根廷等(deng)國(guo)(guo)家(jia)或地區龍(long)卷風(feng)(feng)(feng)發(fa)(fa)生也較為(wei)頻繁(fan)。

年(nian)(nian)(nian)(nian)尺度特征(zheng)美(mei)國(guo)(guo)(guo)龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)風(feng)(feng)平(ping)(ping)(ping)均(jun)(jun)每(mei)(mei)(mei)(mei)年(nian)(nian)(nian)(nian)有(you)(you)(you)(you)(you)1000多(duo)個(ge)(ge)(ge)（1991—2010年(nian)(nian)(nian)(nian)間，平(ping)(ping)(ping)均(jun)(jun)為1253個(ge)(ge)(ge)/年(nian)(nian)(nian)(nian)）。其次為加(jia)拿大(da)(da)，記錄(lu)到(dao)的(de)(de)(de)龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)風(feng)(feng)平(ping)(ping)(ping)均(jun)(jun)約(yue)70個(ge)(ge)(ge)/年(nian)(nian)(nian)(nian)，估計實際發(fa)生的(de)(de)(de)龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)風(feng)(feng)平(ping)(ping)(ping)均(jun)(jun)約(yue)150個(ge)(ge)(ge)/年(nian)(nian)(nian)(nian)。歐洲平(ping)(ping)(ping)均(jun)(jun)觀測到(dao)的(de)(de)(de)龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)風(feng)(feng)大(da)(da)約(yue)有(you)(you)(you)(you)(you)330個(ge)(ge)(ge)/年(nian)(nian)(nian)(nian)，其中(zhong)(zhong)陸(lu)龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)170個(ge)(ge)(ge)，水龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)160個(ge)(ge)(ge)，而(er)實際發(fa)生的(de)(de)(de)龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)風(feng)(feng)大(da)(da)約(yue)有(you)(you)(you)(you)(you)700個(ge)(ge)(ge)/年(nian)(nian)(nian)(nian)，其中(zhong)(zhong)陸(lu)龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)300個(ge)(ge)(ge)，水龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)390個(ge)(ge)(ge)。歐洲龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)風(feng)(feng)多(duo)發(fa)生于(yu)英國(guo)(guo)(guo)、德國(guo)(guo)(guo)、法國(guo)(guo)(guo)和(he)西(xi)班牙：英國(guo)(guo)(guo)（1981—2010年(nian)(nian)(nian)(nian)間）平(ping)(ping)(ping)均(jun)(jun)每(mei)(mei)(mei)(mei)年(nian)(nian)(nian)(nian)大(da)(da)約(yue)有(you)(you)(you)(you)(you) （47.2±10.5）個(ge)(ge)(ge)龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)風(feng)(feng)，其中(zhong)(zhong)陸(lu)龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)（36.5±10.1）個(ge)(ge)(ge)，水龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)（12.7±2.8）個(ge)(ge)(ge)；法國(guo)(guo)(guo)平(ping)(ping)(ping)均(jun)(jun)每(mei)(mei)(mei)(mei)年(nian)(nian)(nian)(nian)有(you)(you)(you)(you)(you)15~20個(ge)(ge)(ge)龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)風(feng)(feng)。亞(ya)洲的(de)(de)(de)龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)風(feng)(feng)主要發(fa)生在中(zhong)(zhong)國(guo)(guo)(guo)、日本(ben)、印度和(he)孟加(jia)拉(la)(la)國(guo)(guo)(guo)：中(zhong)(zhong)國(guo)(guo)(guo)平(ping)(ping)(ping)均(jun)(jun)每(mei)(mei)(mei)(mei)年(nian)(nian)(nian)(nian)發(fa)生的(de)(de)(de)龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)風(feng)(feng)有(you)(you)(you)(you)(you)73個(ge)(ge)(ge)；日本(ben)平(ping)(ping)(ping)均(jun)(jun)每(mei)(mei)(mei)(mei)年(nian)(nian)(nian)(nian)發(fa)生20.5個(ge)(ge)(ge)陸(lu)龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)和(he)4.5個(ge)(ge)(ge)水龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)；孟加(jia)拉(la)(la)國(guo)(guo)(guo)平(ping)(ping)(ping)均(jun)(jun)每(mei)(mei)(mei)(mei)年(nian)(nian)(nian)(nian)發(fa)生的(de)(de)(de)龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)風(feng)(feng)有(you)(you)(you)(you)(you)2個(ge)(ge)(ge)。大(da)(da)洋(yang)洲的(de)(de)(de)龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)風(feng)(feng)主要發(fa)生在澳大(da)(da)利(li)亞(ya)和(he)新(xin)西(xi)蘭：澳大(da)(da)利(li)亞(ya)平(ping)(ping)(ping)均(jun)(jun)每(mei)(mei)(mei)(mei)年(nian)(nian)(nian)(nian)發(fa)生的(de)(de)(de)龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)風(feng)(feng)有(you)(you)(you)(you)(you)29個(ge)(ge)(ge)，新(xin)西(xi)蘭平(ping)(ping)(ping)均(jun)(jun)每(mei)(mei)(mei)(mei)年(nian)(nian)(nian)(nian)發(fa)生的(de)(de)(de)龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)風(feng)(feng)有(you)(you)(you)(you)(you)17個(ge)(ge)(ge)。南美(mei)洲的(de)(de)(de)龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)風(feng)(feng)多(duo)發(fa)于(yu)阿根(gen)(gen)廷(ting)中(zhong)(zhong)部(bu)的(de)(de)(de)潘帕斯草原：阿根(gen)(gen)廷(ting)平(ping)(ping)(ping)均(jun)(jun)每(mei)(mei)(mei)(mei)年(nian)(nian)(nian)(nian)記錄(lu)到(dao)的(de)(de)(de)龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)風(feng)(feng)大(da)(da)概有(you)(you)(you)(you)(you)10個(ge)(ge)(ge)；巴西(xi)、智利(li)和(he)烏拉(la)(la)圭(gui)也有(you)(you)(you)(you)(you)龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)風(feng)(feng)的(de)(de)(de)記錄(lu)，巴西(xi)平(ping)(ping)(ping)均(jun)(jun)每(mei)(mei)(mei)(mei)年(nian)(nian)(nian)(nian)記錄(lu)到(dao)的(de)(de)(de)龍(long)(long)(long)(long)(long)(long)(long)(long)卷(juan)(juan)(juan)(juan)(juan)風(feng)(feng)有(you)(you)(you)(you)(you)3個(ge)(ge)(ge)。

美國的(de)(de)龍(long)卷(juan)(juan)風(feng)多(duo)發(fa)于(yu)春季(ji)(ji)(ji)，其(qi)(qi)次(ci)(ci)(ci)為(wei)(wei)夏季(ji)(ji)(ji)，冬季(ji)(ji)(ji)最(zui)(zui)(zui)少(shao)(shao)發(fa)生(sheng)。歐洲的(de)(de)龍(long)卷(juan)(juan)風(feng)主(zhu)要(yao)發(fa)生(sheng)在(zai)(zai)夏季(ji)(ji)(ji)，其(qi)(qi)次(ci)(ci)(ci)為(wei)(wei)秋季(ji)(ji)(ji)：英國龍(long)卷(juan)(juan)風(feng)主(zhu)要(yao)發(fa)生(sheng)在(zai)(zai)秋季(ji)(ji)(ji)（9—11月(yue)(yue)(yue)），其(qi)(qi)次(ci)(ci)(ci)為(wei)(wei)夏季(ji)(ji)(ji)（6—8月(yue)(yue)(yue)），11月(yue)(yue)(yue)為(wei)(wei)龍(long)卷(juan)(juan)風(feng)發(fa)生(sheng)最(zui)(zui)(zui)多(duo)月(yue)(yue)(yue)；德國2/3的(de)(de)龍(long)卷(juan)(juan)風(feng)發(fa)生(sheng)在(zai)(zai)6—8月(yue)(yue)(yue)，其(qi)(qi)中7月(yue)(yue)(yue)龍(long)卷(juan)(juan)風(feng)發(fa)生(sheng)頻(pin)率達(da)27%；法(fa)國的(de)(de)龍(long)卷(juan)(juan)風(feng)多(duo)發(fa)于(yu)春季(ji)(ji)(ji)和夏季(ji)(ji)(ji)，8月(yue)(yue)(yue)發(fa)生(sheng)最(zui)(zui)(zui)多(duo)；西(xi)班牙的(de)(de)龍(long)卷(juan)(juan)風(feng)多(duo)發(fa)于(yu)暖季(ji)(ji)(ji)，明顯的(de)(de)趨向于(yu)秋季(ji)(ji)(ji)。澳(ao)大利(li)亞(ya)的(de)(de)龍(long)卷(juan)(juan)風(feng)多(duo)發(fa)于(yu)初春和夏季(ji)(ji)(ji)，其(qi)(qi)次(ci)(ci)(ci)為(wei)(wei)初冬。中國龍(long)卷(juan)(juan)風(feng)發(fa)生(sheng)的(de)(de)季(ji)(ji)(ji)節變化(hua)特征明顯，主(zhu)要(yao)集中在(zai)(zai)春夏兩(liang)季(ji)(ji)(ji)，尤(you)以7月(yue)(yue)(yue)和8月(yue)(yue)(yue)最(zui)(zui)(zui)多(duo)，兩(liang)月(yue)(yue)(yue)約占全年總數的(de)(de)50%以上。日本56%的(de)(de)陸龍(long)卷(juan)(juan)發(fa)生(sheng)在(zai)(zai)7—10月(yue)(yue)(yue)，其(qi)(qi)中9月(yue)(yue)(yue)最(zui)(zui)(zui)為(wei)(wei)頻(pin)繁(fan)，3月(yue)(yue)(yue)最(zui)(zui)(zui)少(shao)(shao)；水龍(long)卷(juan)(juan)主(zhu)要(yao)發(fa)生(sheng)在(zai)(zai)9—10月(yue)(yue)(yue)，10月(yue)(yue)(yue)最(zui)(zui)(zui)多(duo)。

美(mei)國(guo)的(de)(de)(de)(de)佛羅里達州和(he)(he)(he)中(zhong)南(nan)(nan)(nan)(nan)部(bu)(bu)(bu)(bu)平(ping)原(yuan)(yuan)是(shi)龍(long)(long)(long)(long)(long)卷(juan)(juan)風(feng)(feng)的(de)(de)(de)(de)高發(fa)(fa)區(qu)，中(zhong)南(nan)(nan)(nan)(nan)部(bu)(bu)(bu)(bu)平(ping)原(yuan)(yuan)稱為“龍(long)(long)(long)(long)(long)卷(juan)(juan)走廊(lang)”，其范圍一般(ban)指從(cong)德克(ke)薩(sa)斯州中(zhong)部(bu)(bu)(bu)(bu)向北到愛荷華州北部(bu)(bu)(bu)(bu)，以及從(cong)堪薩(sa)斯州中(zhong)部(bu)(bu)(bu)(bu)和(he)(he)(he)內(nei)布拉斯加(jia)東(dong)部(bu)(bu)(bu)(bu)到俄亥(hai)俄西(xi)(xi)部(bu)(bu)(bu)(bu)的(de)(de)(de)(de)區(qu)域。英國(guo)的(de)(de)(de)(de)龍(long)(long)(long)(long)(long)卷(juan)(juan)主(zhu)要(yao)發(fa)(fa)生(sheng)于(yu)(yu)英格蘭的(de)(de)(de)(de)東(dong)部(bu)(bu)(bu)(bu)和(he)(he)(he)南(nan)(nan)(nan)(nan)部(bu)(bu)(bu)(bu)以及海(hai)(hai)峽群島周邊(bian)。德國(guo)的(de)(de)(de)(de)龍(long)(long)(long)(long)(long)卷(juan)(juan)風(feng)(feng)多(duo)(duo)發(fa)(fa)于(yu)(yu)沿海(hai)(hai)和(he)(he)(he)丘陵地(di)區(qu)。法國(guo)的(de)(de)(de)(de)龍(long)(long)(long)(long)(long)卷(juan)(juan)風(feng)(feng)多(duo)(duo)發(fa)(fa)于(yu)(yu)西(xi)(xi)北部(bu)(bu)(bu)(bu)、南(nan)(nan)(nan)(nan)部(bu)(bu)(bu)(bu)和(he)(he)(he)東(dong)部(bu)(bu)(bu)(bu)。西(xi)(xi)班(ban)牙的(de)(de)(de)(de)龍(long)(long)(long)(long)(long)卷(juan)(juan)風(feng)(feng)多(duo)(duo)發(fa)(fa)于(yu)(yu)地(di)中(zhong)海(hai)(hai)區(qu)域和(he)(he)(he)加(jia)的(de)(de)(de)(de)斯灣附近省(sheng)(sheng)(sheng)(sheng)份。中(zhong)國(guo)龍(long)(long)(long)(long)(long)卷(juan)(juan)風(feng)(feng)一般(ban)多(duo)(duo)發(fa)(fa)生(sheng)在中(zhong)東(dong)部(bu)(bu)(bu)(bu)地(di)形相對(dui)平(ping)坦的(de)(de)(de)(de)平(ping)原(yuan)(yuan)地(di)區(qu)，平(ping)原(yuan)(yuan)多(duo)(duo)于(yu)(yu)山區(qu)；從(cong)區(qu)域尺(chi)(chi)度來看(kan)，長(chang)江(jiang)(jiang)三(san)角(jiao)洲、蘇(su)北、魯西(xi)(xi)南(nan)(nan)(nan)(nan)、豫東(dong)等平(ping)原(yuan)(yuan)、湖沼區(qu)以及雷(lei)州半島等地(di)都(dou)是(shi)龍(long)(long)(long)(long)(long)卷(juan)(juan)風(feng)(feng)的(de)(de)(de)(de)易發(fa)(fa)區(qu)；從(cong)省(sheng)(sheng)(sheng)(sheng)級行(xing)政單(dan)元(yuan)尺(chi)(chi)度來看(kan)，江(jiang)(jiang)蘇(su)省(sheng)(sheng)(sheng)(sheng)、安(an)徽省(sheng)(sheng)(sheng)(sheng)、廣東(dong)省(sheng)(sheng)(sheng)(sheng)、河南(nan)(nan)(nan)(nan)省(sheng)(sheng)(sheng)(sheng)、湖北省(sheng)(sheng)(sheng)(sheng)是(shi)龍(long)(long)(long)(long)(long)卷(juan)(juan)風(feng)(feng)多(duo)(duo)發(fa)(fa)的(de)(de)(de)(de)省(sheng)(sheng)(sheng)(sheng)份，黑龍(long)(long)(long)(long)(long)江(jiang)(jiang)省(sheng)(sheng)(sheng)(sheng)、河北省(sheng)(sheng)(sheng)(sheng)、浙江(jiang)(jiang)省(sheng)(sheng)(sheng)(sheng)、江(jiang)(jiang)西(xi)(xi)省(sheng)(sheng)(sheng)(sheng)和(he)(he)(he)湖南(nan)(nan)(nan)(nan)省(sheng)(sheng)(sheng)(sheng)等省(sheng)(sheng)(sheng)(sheng)份龍(long)(long)(long)(long)(long)卷(juan)(juan)風(feng)(feng)的(de)(de)(de)(de)發(fa)(fa)生(sheng)頻次較高。1961—1993年間日(ri)本的(de)(de)(de)(de)陸龍(long)(long)(long)(long)(long)卷(juan)(juan)和(he)(he)(he)水(shui)龍(long)(long)(long)(long)(long)卷(juan)(juan)主(zhu)要(yao)發(fa)(fa)生(sheng)在沿海(hai)(hai)地(di)區(qu)，而(er)關東(dong)地(di)區(qu)大量龍(long)(long)(long)(long)(long)卷(juan)(juan)風(feng)(feng)遠離沿海(hai)(hai)區(qu)域。大洋洲的(de)(de)(de)(de)龍(long)(long)(long)(long)(long)卷(juan)(juan)風(feng)(feng)主(zhu)要(yao)發(fa)(fa)生(sheng)在澳大利亞和(he)(he)(he)新(xin)西(xi)(xi)蘭。澳大利亞的(de)(de)(de)(de)龍(long)(long)(long)(long)(long)卷(juan)(juan)風(feng)(feng)主(zhu)要(yao)發(fa)(fa)生(sheng)于(yu)(yu)東(dong)南(nan)(nan)(nan)(nan)部(bu)(bu)(bu)(bu)和(he)(he)(he)西(xi)(xi)南(nan)(nan)(nan)(nan)部(bu)(bu)(bu)(bu)。南(nan)(nan)(nan)(nan)美(mei)洲的(de)(de)(de)(de)龍(long)(long)(long)(long)(long)卷(juan)(juan)風(feng)(feng)多(duo)(duo)發(fa)(fa)于(yu)(yu)阿根廷中(zhong)部(bu)(bu)(bu)(bu)的(de)(de)(de)(de)潘(pan)帕斯草原(yuan)(yuan)。巴西(xi)(xi)龍(long)(long)(long)(long)(long)卷(juan)(juan)多(duo)(duo)發(fa)(fa)于(yu)(yu)南(nan)(nan)(nan)(nan)部(bu)(bu)(bu)(bu)和(he)(he)(he)東(dong)南(nan)(nan)(nan)(nan)部(bu)(bu)(bu)(bu)。

中國龍卷風

我國大部分省(sheng)（區、市）都(dou)有(you)龍卷(juan)風(feng)(feng)的(de)蹤(zong)跡，主(zhu)要(yao)發(fa)生在我國東部平(ping)原(yuan)地區，1991年-2014年，我國平(ping)均每年有(you)43個(ge)龍卷(juan)風(feng)(feng)，其中江蘇和廣(guang)東最多(duo)，年均龍卷(juan)風(feng)(feng)分別(bie)為5.5個(ge)和4.8個(ge)。春(chun)季、夏季是(shi)龍卷(juan)風(feng)(feng)的(de)多(duo)發(fa)季節，4-8月龍卷(juan)風(feng)(feng)占全年的(de)92%。

預測難點

直徑小

龍(long)(long)卷(juan)風(feng)是(shi)一(yi)種破壞力極強(qiang)的(de)(de)小(xiao)尺度(du)天氣(qi)現象，直(zhi)徑一(yi)般在100米(mi)以下，強(qiang)龍(long)(long)卷(juan)可(ke)達(da)幾(ji)百米(mi)到1千米(mi)左(zuo)右。相比于(yu)臺風(feng)、副高這些天氣(qi)系(xi)統中的(de)(de)“大塊頭”，龍(long)(long)卷(juan)風(feng)絕對屬于(yu)“小(xiao)個子”。而當(dang)前我們(men)的(de)(de)氣(qi)象臺站(zhan)不夠密集，以至于(yu)龍(long)(long)卷(juan)風(feng)經常躲(duo)過(guo)氣(qi)象監測的(de)(de)“法眼”。

持續時間短

龍卷風強(qiang)對流(liu)天(tian)氣(qi)往往生(sheng)成很突然，對某一地(di)區(qu)的影響(xiang)時(shi)間(jian)也(ye)相對較短(duan)，“生(sheng)命(ming)史”只有十幾(ji)分鐘到個把(ba)小時(shi)。因(yin)此，要提(ti)前24小時(shi)或(huo)是48小時(shi)預(yu)報(bao)局部地(di)區(qu)的強(qiang)對流(liu)天(tian)氣(qi)也(ye)就非常(chang)困難了。

形成環境復雜

龍卷風等強對流天氣的(de)生成(cheng)和發展需要衡量綜合大氣條件，而(er)這些(xie)條件往(wang)往(wang)是難以(yi)預料、不確(que)切的(de)，再加上不同地區(qu)之間各不相同的(de)地形因素(su)，也進一步增加了準確(que)監測、預報的(de)難度。

防范措施

（1）龍卷(juan)風發生是和(he)(he)強烈發展的(de)積雨(yu)云聯(lian)系在(zai)一(yi)起的(de)，也就是通常(chang)所(suo)(suo)說的(de)雷(lei)雨(yu)云。龍卷(juan)風出(chu)(chu)現(xian)時天(tian)空往往烏天(tian)黑(hei)地(di)(di)(di)(di)（云層(ceng)低而深厚、亮度(du)差）、電(dian)閃雷(lei)鳴、風雨(yu)交加。以(yi)春未到(dao)(dao)秋(qiu)初最常(chang)見，在(zai)一(yi)天(tian)中以(yi)下(xia)午(wu)至傍晚(wan)和(he)(he)凌晨(chen)至早晨(chen)出(chu)(chu)現(xian)最多(duo)。當看到(dao)(dao)天(tian)空有類似(si)的(de)癥兆就要引(yin)起注意。人群(qun)應(ying)立刻離開危險房屋(wu)、活(huo)動場所(suo)(suo)或其他簡易臨時住處，到(dao)(dao)附(fu)近比較堅固(gu)的(de)房屋(wu)內躲避。在(zai)公(gong)共場所(suo)(suo)，要服從指(zhi)(zhi)揮，有秩序(xu)地(di)(di)(di)(di)向指(zhi)(zhi)定地(di)(di)(di)(di)點疏散(san)。躲避龍卷(juan)風最為(wei)安全的(de)地(di)(di)(di)(di)方是位于地(di)(di)(di)(di)下(xia)的(de)空間或場所(suo)(suo)（如地(di)(di)(di)(di)下(xia)室或半(ban)地(di)(di)(di)(di)下(xia)室），地(di)(di)(di)(di)面上所(suo)(suo)有建筑(zhu)物此(ci)時都不是安全躲避的(de)場所(suo)(suo)。

（2）在野外遇到(dao)龍(long)卷(juan)(juan)風(feng)襲擊時，不必(bi)驚慌失措(cuo)，應(ying)迅速(su)朝龍(long)卷(juan)(juan)風(feng)移(yi)動方(fang)(fang)向的(de)垂(chui)直方(fang)(fang)向跑(pao)動，伏于低(di)洼地面、溝渠等，但要遠離(li)大(da)樹(shu)、電線桿、廣告牌、圍(wei)墻等，以(yi)免被砸(za)、被壓或發生觸電事(shi)故。如在汽車(che)中(zhong)，應(ying)及時離(li)開(kai)，到(dao)低(di)洼地躲避，因為汽車(che)本身沒(mei)有防御龍(long)卷(juan)(juan)風(feng)能力，一旦汽車(che)和人同時被龍(long)卷(juan)(juan)風(feng)卷(juan)(juan)起，危(wei)害(hai)更大(da)。

（3）在(zai)家遇到(dao)龍(long)(long)卷(juan)(juan)(juan)風(feng)(feng)時，遠離和(he)龍(long)(long)卷(juan)(juan)(juan)風(feng)(feng)同方向的(de)(de)(de)窗(chuang)、門、房屋的(de)(de)(de)外圍墻壁，盡可能(neng)在(zai)龍(long)(long)卷(juan)(juan)(juan)風(feng)(feng)相反方向角落或比(bi)較(jiao)堅固(gu)的(de)(de)(de)小房間(jian)抱頭(tou)蹲下(xia)，保護好自(zi)己(ji)的(de)(de)(de)頭(tou)部。在(zai)樓上，特別是農村的(de)(de)(de)樓房內，應立即暫避到(dao)一樓比(bi)較(jiao)堅固(gu)的(de)(de)(de)桌子底下(xia)或廁所、儲物間(jian)內。這是因為龍(long)(long)卷(juan)(juan)(juan)風(feng)(feng)中心的(de)(de)(de)氣壓(ya)極低，容易被龍(long)(long)卷(juan)(juan)(juan)風(feng)(feng)外吸、房屋倒塌而殃及(ji)室內人(ren)員(yuan)安全。

（4）在(zai)遭(zao)(zao)遇龍卷(juan)風(feng)和(he)發生(sheng)房屋倒塌(ta)、電(dian)桿折(zhe)斷的(de)情(qing)況下，應(ying)(ying)及時(shi)切斷電(dian)源，以防(fang)觸電(dian)和(he)引發火災(zai)事(shi)故。如果(guo)是化(hua)(hua)工生(sheng)產企業(ye)遭(zao)(zao)受龍卷(juan)風(feng)襲擊，應(ying)(ying)及時(shi)關閉有毒化(hua)(hua)學(xue)物品(pin)閥門，控制(zhi)化(hua)(hua)學(xue)物品(pin)泄漏，防(fang)止污染源向土壤和(he)水面擴散，必(bi)要時(shi)組織附近市(shi)（村(cun)）民(min)緊急轉移(yi)。

（5）龍(long)(long)卷(juan)(juan)(juan)風后自(zi)救(jiu)(jiu)互救(jiu)(jiu)。由于(yu)龍(long)(long)卷(juan)(juan)(juan)風的(de)風力(li)特別(bie)大(da)，具有巨大(da)的(de)破(po)壞(huai)作用，龍(long)(long)卷(juan)(juan)(juan)經過的(de)區域內，房屋等(deng)建(jian)筑物常會(hui)遭受不(bu)同程度(du)(du)的(de)破(po)壞(huai)，甚至發生(sheng)倒塌。因此，受龍(long)(long)卷(juan)(juan)(juan)影響地區的(de)群眾(zhong)，尤其是家庭(ting)、鄰(lin)里(li)之(zhi)間(jian)(jian)在災后第一時間(jian)(jian)的(de)自(zi)救(jiu)(jiu)互救(jiu)(jiu)可最大(da)限度(du)(du)減少人員(yuan)傷亡。被(bei)(bei)埋壓人員(yuan)要(yao)(yao)保持清(qing)醒(xing)頭腦，盡快想(xiang)法(fa)脫(tuo)離險(xian)境，如果(guo)不(bu)能自(zi)我脫(tuo)險(xian)時，應盡量(liang)創造(zao)和擴大(da)安(an)全生(sheng)存空間(jian)(jian)，減少對(dui)身體的(de)擠(ji)壓，特別(bie)是對(dui)腹部以上身體部位的(de)壓物要(yao)(yao)清(qing)除或移(yi)開，加(jia)強(qiang)對(dui)頭部及口、鼻等(deng)器官(guan)的(de)自(zi)我保護，等(deng)待救(jiu)(jiu)援(yuan)。救(jiu)(jiu)援(yuan)時要(yao)(yao)講究方法(fa)，首先應使被(bei)(bei)救(jiu)(jiu)者(zhe)暴(bao)露(lu)頭部，保持呼吸(xi)暢通(tong)，如有窒息(xi)，應立即進(jin)行人工呼吸(xi)。其次不(bu)可生(sheng)拉硬(ying)扯或使用利器硬(ying)挖被(bei)(bei)埋者(zhe)，以免造(zao)成進(jin)一步的(de)損傷，同時對(dui)傷重者(zhe)及時送醫院搶(qiang)救(jiu)(jiu)。